CN115102327A

CN115102327A - Waterproof dustproof electric putter

Info

Publication number: CN115102327A
Application number: CN202210698524.7A
Authority: CN
Inventors: 尹亮
Original assignee: Hanwan Zhong
Current assignee: Hanwan Zhong
Priority date: 2022-06-20
Filing date: 2022-06-20
Publication date: 2022-09-23
Also published as: US20220403938A1; US12085173B2

Abstract

The invention relates to the field of push rods, in particular to a waterproof and dustproof electric push rod which comprises a driving module, an outer tube assembly, an inner tube, a screw rod and a sliding nut, wherein the screw rod and the inner tube are positioned in the outer tube assembly; the waterproof and dustproof module is clamped between the inner pipe and the outer pipe assembly and comprises a single-lip oil seal, a first anti-swing ring, a piston oil seal and a second anti-swing ring which are sequentially arranged along the retraction direction of the inner pipe.

Description

Waterproof dustproof electric putter

Technical Field

The invention relates to the field of push rods, in particular to a waterproof and dustproof electric push rod.

Background

The electric push rod is an electric driving device which converts the rotary motion of a motor into the linear reciprocating motion of the push rod. The device can be used as an execution machine in various simple or complex process flows to realize remote control, centralized control or automatic control. The motion driving unit is widely used in the industries of household appliances, kitchen ware, medical appliances, automobiles and the like.

The existing electric push rod is not provided with a corresponding waterproof or dustproof structure, the use environment of the electric push rod is changeable, the electric push rod exposed on the outer wall of the push rod in an outdoor environment inevitably occupies certain silt/water vapor/dust, when the push rod is driven by a motor to retract, the silt/water vapor/dust on the outer wall of the push rod can directly enter the push rod, and the water vapor can corrode an internal structure or an internal circuit for a long time, and simultaneously, rusting and other conditions which influence normal work are easily caused;

therefore, the inventor has endeavored to design a waterproof and dustproof electric putter to solve the above problems.

Disclosure of Invention

In order to solve the problems, the invention provides a waterproof and dustproof electric push rod, which is characterized in that a single-lip oil seal, a first anti-swing ring, a piston oil seal and a second anti-swing ring are arranged, inner rings of the single-lip oil seal, the first anti-swing ring, the piston oil seal and the second anti-swing ring are tightly attached to the outer side wall of an inner pipe, when the inner pipe retracts, the single-lip oil seal plays a role in scraping dirt (dust, silt and the like) on the surface of the inner pipe due to the fact that the inner rings of the single-lip oil seal, the first anti-swing ring, the piston oil seal and the second anti-swing ring are tightly attached to the outer side wall of the inner pipe, and the inner piston oil seal plays a role in preventing water and dust.

In order to realize the purpose, the invention adopts the technical scheme that: a waterproof and dustproof electric push rod comprises a driving module, an outer tube assembly, an inner tube, a screw rod and a sliding nut, wherein the screw rod and the inner tube are positioned in the outer tube assembly; the waterproof and dustproof module is clamped between the inner pipe and the outer pipe assembly and comprises a single-lip oil seal, a first anti-swing ring, a piston oil seal and a second anti-swing ring which are sequentially arranged along the retraction direction of the inner pipe, and inner rings of the single-lip oil seal, the first anti-swing ring, the piston oil seal and the second anti-swing ring are tightly attached to the outer side wall of the inner pipe.

Furthermore, the first inside wall of preventing the swing ring and the second prevents the swing ring is provided with a plurality of circles of screw thread oil storage tanks, and constitutes the oil storage cavity between this screw thread oil storage tank and the inner tube lateral wall.

Further, the outer tube subassembly includes outer tube body and fixed end cover, and wherein the front end of outer tube body is provided with an opening, and the fixed end cover lid closes at this opening part, and the center department of this fixed end cover is provided with the export of letting that supplies the inner tube to wear out.

Furthermore, a plurality of sliding teeth are convexly arranged on the inner wall of the outer tube body at intervals; the sliding nut comprises a sliding connection assembly and a sliding sleeve, wherein an internal thread is arranged on the inner wall of the sliding connection assembly, an external thread is arranged at one end of the sliding connection assembly, the other end of the sliding connection assembly is sleeved with the sliding sleeve, a plurality of sliding grooves are arranged on the outer wall of the sliding sleeve, each sliding groove is arranged along the axial direction of the sliding sleeve, and a plurality of sliding teeth of the outer pipe are matched with a plurality of sliding grooves of the sliding sleeve in a one-to-one correspondence manner.

Furthermore, the back of the fixed end cover is provided with an oil seal assembling groove corresponding to the position of the outlet, wherein the single-lip oil seal is assembled in the oil seal assembling groove in a sealing way through a sealing ring, and the surface of the oil seal assembling groove is covered with a sealing cover.

Furthermore, the sliding teeth of the outer pipe body are tightly attached to the outer rings of the first anti-swing ring, the piston oil seal and the second anti-swing ring.

Further, the sliding connection assembly comprises a sliding block and a threaded sleeve, the sliding block and the sliding sleeve are both annular, the internal thread is arranged on the inner wall of the threaded sleeve, the sliding block is sleeved outside the threaded sleeve, the sliding block and the threaded sleeve are positioned through two positioning screws, the two positioning screws are axially arranged between the sliding block and the threaded sleeve, one part of the same positioning screw is positioned on an inner wall groove of the sliding block, the other part of the positioning screw is positioned on an outer wall groove of the threaded sleeve, and the two positioning screws are positioned on the end faces of the sliding block and the threaded sleeve and are oppositely arranged.

Further, the external screw thread is located the outer wall of slider, and the slider is kept away from one end outer wall of its external screw thread and is equipped with a plurality of side channels, many rings of recesses and an annular spacing platform, and a plurality of side channels set up along the axial of slider, and many rings of recesses set up along the radial of slider, and a plurality of side channels and many rings of recess cross intercommunication, spacing platform are located between many rings of recesses and the external screw thread.

Further, the inner wall of sliding sleeve and the outer wall of slider rotate spacing cooperation, and the outer wall of sliding sleeve outwards extends has a spacing portion, is equipped with a plurality of material holes of drawing on the terminal surface of sliding sleeve, and when the sliding sleeve cover was located on the slider, external screw thread and spacing platform on the slider were located outside the sliding sleeve.

Further, still be equipped with two on the inner wall of outer tube body and hang groove and a location portion, a plurality of smooth teeth, two hang grooves and location portion all set up along the axial of outer tube body, it has a mount to hang along its axial on the inner wall of outer tube body, the both ends of mount are equipped with the platform of hanging of rectangular shape respectively, two platforms cooperate with two of outer tube body's two string groove one-to-one respectively, the one end that the outer tube body was kept away from to the mount is equipped with a constant head tank, this constant head tank cooperates with the location portion of outer tube body, the both ends of mount are fixed with micro-gap switch respectively, sliding sleeve 1 is located between two micro-gap switch, the spacing position of sliding sleeve is in the side of mount.

The invention has the beneficial effects that: 1. the driving module drives the screw rod to rotate, the screw rod drives the whole sliding nut to slide in a reciprocating manner in the outer pipe, and the inner pipe is stretched and retracted, meanwhile, in the application, the waterproof and dustproof module comprises a single-lip oil seal, a first anti-swing ring, a piston oil seal and a second anti-swing ring which are sequentially arranged along the retracting direction of the inner pipe, when the inner pipe retracts, because inner rings of the single-lip oil seal, the first anti-swing ring, the piston oil seal and the second anti-swing ring are tightly attached to the outer side wall of the inner pipe, the single-lip oil seal plays a role in scraping dirt (dust, silt and the like) on the surface of the inner pipe, and the inner piston oil seal plays a role in preventing water and dust;

2. in addition, the inner side wall of the first anti-swing ring and the second anti-swing ring is provided with a plurality of circles of thread oil storage grooves, and if a front single-lip oil seal is adopted, sand and dust need to slowly move upwards through the direction of the thread oil storage grooves, so that the sand and dust can not easily enter, the inner pipe can be lubricated more by coating lubricating grease in the thread oil storage grooves during assembly, grease can be stored in the inner pipe, and therefore the inner pipe stretches out or retracts every time, and the first anti-swing ring and the second anti-swing ring can both play a role in lubrication.

3. The sliding teeth of the outer pipe body are tightly attached to the outer rings of the first anti-swing ring, the piston oil seal and the second anti-swing ring, the seat machining piece is supported at the front end, the first anti-swing ring and the second anti-swing ring are arranged, die-casting drawing angles are omitted, the seat machining piece is attached to the inner wall of the outer pipe, supporting force and concentricity are more compact and better, and the inner pipe swings less.

Drawings

FIG. 1 is an exploded perspective view of the power putter of the present invention;

FIG. 2 is a schematic perspective view of the electric putter without the outer tube and the fixing frame;

FIG. 3 is a schematic perspective view of the driving module and the inner tube of FIG. 2;

FIG. 4 is a cross-sectional view of FIG. 3;

FIG. 5 is an enlarged view at B in FIG. 4;

FIG. 6 is a perspective view of the slip nut of the present invention;

FIG. 7 is a perspective view of another perspective of the slip nut of the present invention;

fig. 8 is a perspective exploded perspective view of the slip nut of the present invention;

FIG. 9 is a schematic view of a three-dimensional structure of the present invention without a driving module;

FIG. 10 is an enlarged view taken at A in FIG. 9;

FIG. 11 is an enlarged perspective view of the telescoping rod of the present invention with the outer tube body and the waterproof and dustproof module removed;

fig. 12 is an enlarged perspective view of the outer tube and the fixing frame of the present invention.

The reference numbers indicate: the sliding sleeve comprises a sliding sleeve 1, a sliding groove 11, a material drawing hole 12, a limiting part 13, a sliding block 2, a side groove 21, a groove 22, a limiting table 23, a threaded sleeve 3, a positioning screw 31, an outer tube body 4, a fixing frame 41, a hanging table 411, a positioning groove 412, a micro switch 42, a sliding tooth 43, a screw rod 5, a driven gear 51, an inner tube 6, a motor 7, a driving gear 71, a base 8, a fixing end cover 9, a single-lip oil seal 90, a first anti-swing ring 91, a second anti-swing ring 92, a thread oil storage groove 920, a piston oil seal 93, a sealing ring 94 and a sealing cover 95.

Detailed Description

Referring to fig. 1-12, the present invention relates to a waterproof and dustproof electric push rod, which includes a driving module, an outer tube assembly, an inner tube 6, a screw rod 5, and a sliding nut, wherein the screw rod 5 and the inner tube 6 are both located in the outer tube assembly, wherein the sliding nut is movably assembled on the screw rod 5, the driving module is in driving connection with the screw rod 5, the inner tube 6 is sleeved on a limiting nut and extends to the outside of the outer tube assembly or retracts into the outer tube assembly along the length direction of the screw rod 5; waterproof and dustproof modules are clamped between the inner tube 6 and the outer tube assembly, wherein each waterproof and dustproof module comprises a single-lip oil seal 90, a first anti-swing ring 91, a piston oil seal 93 and a second anti-swing ring 92 which are sequentially arranged along the retraction direction of the inner tube 6, and inner rings of the single-lip oil seal 90, the first anti-swing ring 91, the piston oil seal 93 and the second anti-swing ring 92 are tightly attached to the outer side wall of the inner tube 6.

The driving module drives the screw rod 5 to rotate, the screw rod 5 drives the whole sliding nut to slide in the outer pipe in a reciprocating manner, and the telescopic action of the inner pipe 6 is realized, meanwhile, in the application, the waterproof and dustproof module comprises a single-lip oil seal 90, a first anti-swing ring 91, a piston oil seal 93 and a second anti-swing ring 92 which are sequentially arranged along the retraction direction of the inner pipe 6, inner rings of the single-lip oil seal 90, the first anti-swing ring 91, the piston oil seal 93 and the second anti-swing ring 92 are tightly attached to the outer side wall of the inner pipe 6, when the inner pipe 6 retracts, because the inner rings of the single-lip oil seal 90, the first anti-swing ring 91, the piston oil seal 93 and the second anti-swing ring 92 are tightly attached to the outer side wall of the inner pipe 6, the single-lip oil seal 90 plays a role in scraping dirt (dust, silt and the like) on the surface of the inner pipe 6, and the piston oil seal 93 has waterproof and dustproof effects;

it should be noted that the single-lip oil seal 90 and the piston oil seal 93 used in the present application are commercially available products, and thus the specific structure thereof will not be discussed redundantly.

Referring to fig. 5, a plurality of circles of thread oil storage grooves 920 are disposed on the inner side walls of the first anti-swing ring 91 and the second anti-swing ring 92, and an oil storage cavity is formed between the thread oil storage grooves 920 and the outer side wall of the inner tube 6.

In addition, the inner side wall of the first anti-swing ring 91 and the second anti-swing ring 92 is provided with a plurality of circles of thread oil storage grooves 920, if a front single-lip oil seal 90 is arranged, sand and dust need to slowly move upwards in the direction of the thread oil storage grooves 920, the sand and dust can not easily enter, the inner pipe 6 can be lubricated more by applying lubricating grease in the thread oil storage grooves 920 during assembly, grease can be stored inside the inner pipe, and therefore the inner pipe 6 stretches out or retracts every time, and the first anti-swing ring 91 and the second anti-swing ring 92 both play a lubricating role.

Further, the outer tube assembly comprises an outer tube body 4 and a fixed end cover 9, wherein an opening is formed in the front end of the outer tube body 4, the fixed end cover 9 covers the opening, and a yielding opening for the inner tube 6 to penetrate out is formed in the center of the fixed end cover 9.

Referring to fig. 12, further, a plurality of sliding teeth 43 are protruded on the inner wall of the outer tube body 4 at intervals; the sliding nut comprises a sliding connection component and a sliding sleeve 1, wherein an internal thread is arranged on the inner wall of the sliding connection component, an external thread is arranged at one end of the sliding connection component, the sliding sleeve 1 is sleeved at the other end of the sliding connection component, a plurality of sliding grooves 11 are arranged on the outer wall of the sliding sleeve 1, each sliding groove 11 is arranged along the axial direction of the sliding sleeve 1, and a plurality of sliding teeth 43 of the outer pipe are matched with the plurality of sliding grooves 11 of the sliding sleeve 1 in a one-to-one correspondence manner.

The outer tube body 4 is long tubular, and the interval is protruding to be equipped with a plurality of sliding teeth 43 on the inner wall of outer tube body 4, and when whole slip nut slided in the outer tube, a plurality of sliding teeth 43 of outer tube body 4 and a plurality of spout 11 one-to-one cooperation of sliding sleeve 1 made the relative outer tube body 4 of inner tube 6 slide more steadily.

Further, an oil seal assembling slot is arranged at the position of the back surface of the fixed end cover 9 corresponding to the outlet, wherein the single-lip oil seal 90 is hermetically assembled in the oil seal assembling slot through a sealing ring 94, and a sealing cover 95 covers the surface of the oil seal assembling slot. In this embodiment, the single-lip oil seal 90 is sealingly fitted in the oil seal fitting groove by the seal ring 94, so that the sealing performance can be further improved, and the single-lip oil seal 90 can be prevented from being displaced, so that the surface of the oil seal fitting groove is covered with the seal cover 95.

Further, the sliding teeth 43 of the outer tube body 4 are closely attached to the outer rings of the first anti-swing ring 91, the piston oil seal 93 and the second anti-swing ring 92.

The sliding teeth 43 of the outer tube body 4 are tightly attached to the outer rings of the first anti-swing ring 91, the piston oil seal 93 and the second anti-swing ring 92, the seat machining piece is supported by the front end of the outer tube body through the first anti-swing ring 91 and the second anti-swing ring 92, die-casting drawing angles are omitted, the outer tube body is attached to the inner wall of the outer tube more compactly, supporting force and concentricity are better, and the inner tube 6 swings less.

Referring to fig. 6-8, further, the sliding connection assembly includes a sliding block 2 and a threaded sleeve 3, the sliding block 2 and the sliding sleeve 1 are both annular, the internal thread is disposed on an inner wall of the threaded sleeve 3, the sliding block 2 is sleeved outside the threaded sleeve 3, the sliding block 2 and the threaded sleeve 3 are positioned by two positioning screws 31, the two positioning screws 31 are axially disposed between the sliding block 2 and the threaded sleeve 3, a portion of the same positioning screw 31 is disposed on an inner wall groove of the sliding block 2, another portion of the same positioning screw 31 is disposed on an outer wall groove of the threaded sleeve 3, and the two positioning screws 31 are disposed on end faces of the sliding block 2 and the threaded sleeve 3 and are oppositely disposed.

The sliding connection assembly comprises a sliding block 2 and a threaded sleeve 3, the sliding block 2 and the sliding sleeve 1 are both annular, the internal thread is arranged on the inner wall of the threaded sleeve 3, the sliding block 2 is sleeved outside the threaded sleeve 3, in the embodiment, the outer wall of the threaded sleeve 3 is connected with the inner wall of the sliding block 2 through threads, the sliding block 2 and the threaded sleeve 3 move together, in order to prevent the threaded sleeve 3 from rotating relative to the sliding block 2, the sliding block 2 and the threaded sleeve 3 are positioned through two positioning screws 31, the two positioning screws 31 are axially arranged between the sliding block 2 and the threaded sleeve 3, one part of the same positioning screw 31 is positioned on the inner wall groove of the sliding block 2, the other part of the positioning screw 31 is positioned on the outer wall groove of the threaded sleeve 3, and the two positioning screws 31 are positioned on the end faces of the sliding block 2 and the threaded sleeve 3 and are oppositely arranged.

Further, the external screw thread is located the outer wall of slider 2, is equipped with a plurality of side channels 21, many rings of recess 22 and an annular spacing platform 23 on the slider 2 keeps away from its external screw thread's one end outer wall, and a plurality of side channels 21 set up along the axial of slider 2, and many rings of recess 22 set up along the radial of slider 2, and a plurality of side channels 21 and many rings of recess 22 alternately communicate, and spacing platform 23 is located between many rings of recess 22 and the external screw thread.

Referring to fig. 8, further, the inner wall of the sliding sleeve 1 is in rotational limit fit with the outer wall of the sliding block 2, the outer wall of the sliding sleeve 1 extends outward to form a limit portion 13, the end face of the sliding sleeve 1 is provided with a plurality of material taking holes 12, and when the sliding sleeve 1 is sleeved on the sliding block 2, the external thread on the sliding block 2 and the limit table 23 are located outside the sliding sleeve 1. When the sliding sleeve 1 is sleeved on the sliding block 2, the external thread and the limiting table 23 on the sliding block 2 are positioned outside the sliding sleeve 1.

Referring to fig. 9-12, further, the inner wall of the outer tube body 4 is further provided with two hanging grooves and a positioning portion, the plurality of sliding teeth 43, the two hanging grooves and the positioning portion are all arranged along the axial direction of the outer tube body 4, the inner wall of the outer tube body 4 is connected with a fixing frame 41 along the axial direction thereof, two ends of the fixing frame 41 are respectively provided with a strip-shaped hanging platform 411, the two hanging platforms 411 are respectively matched with the two hanging grooves of the outer tube body 4 in a one-to-one correspondence manner, one end of the fixing frame 41 away from the outer tube body 4 is provided with a positioning groove 412, the positioning groove 412 is matched with the positioning portion of the outer tube body 4, two ends of the fixing frame 41 are respectively fixed with a micro switch 42, the sliding sleeve 1 is located between the two micro switches 42, and the limiting portion 13 of the sliding sleeve 1 is located beside the fixing frame 41.

The whole sliding nut can slide between the two micro switches 42, when the limiting part 13 of the sliding sleeve 1 touches one of the micro switches 42, the internal circuit board can control the motor 7 to stop working, and the positions of the two micro switches 42 determine the upper and lower limit values of the up-and-down movement of the inner tube 6.

The screw 5 penetrates through the threaded sleeve 3 in a threaded manner, namely the outer wall of the screw 5 is in threaded connection with the threaded sleeve 3, one end, close to the nut, of the inner tube 6 is sleeved on the outer thread of the sliding block 2 and abuts against the limiting table 23 of the sliding block, and therefore the inner tube 6 is fixedly connected with the sliding block 2 through threads.

The driving module in this embodiment includes a motor 7, a driving gear 71 is disposed at an output end of the motor 7, a driven gear 51 is disposed on the lead screw 5 of the telescopic rod, the driving gear 71 is engaged with the driven gear 51 through a plurality of transmission gears, and the driving gear 71, the transmission gears and the driven gear 51 are disposed in a base 8.

The above embodiments are only for describing the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the design of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A waterproof and dustproof electric push rod is characterized by comprising a driving module, an outer tube assembly, an inner tube, a screw rod and a sliding nut, wherein the screw rod and the inner tube are positioned in the outer tube assembly; the waterproof and dustproof module is clamped between the inner pipe and the outer pipe assembly and comprises a single-lip oil seal, a first anti-swing ring, a piston oil seal and a second anti-swing ring which are sequentially arranged along the retraction direction of the inner pipe, and inner rings of the single-lip oil seal, the first anti-swing ring, the piston oil seal and the second anti-swing ring are tightly attached to the outer side wall of the inner pipe.

2. A telescopic rod according to claim 1, characterized in that: the inner side wall of the first anti-swing ring and the second anti-swing ring is provided with a plurality of circles of thread oil storage grooves, and an oil storage cavity is formed between each thread oil storage groove and the outer side wall of the inner pipe.

3. The waterproof dustproof electric push rod of claim 1, characterized in that: the outer tube subassembly includes outer tube body and fixed end cover, and wherein the front end of outer tube body is provided with an opening, and the fixed end cover lid closes at this opening part, and the center department of this fixed end cover is provided with the export of letting that supplies the inner tube to wear out.

4. The waterproof dustproof electric putter of claim 3, characterized in that: a plurality of sliding teeth are convexly arranged on the inner wall of the outer tube body at intervals; the sliding nut comprises a sliding connection assembly and a sliding sleeve, wherein an internal thread is arranged on the inner wall of the sliding connection assembly, an external thread is arranged at one end of the sliding connection assembly, the sliding sleeve is sleeved at the other end of the sliding connection assembly, a plurality of sliding grooves are arranged on the outer wall of the sliding sleeve, each sliding groove is arranged along the axial direction of the sliding sleeve, and a plurality of sliding teeth of the outer pipe 4 are matched with a plurality of sliding grooves of the sliding sleeve in a one-to-one correspondence manner.

5. The waterproof dustproof electric putter of claim 4, characterized in that: the back of the fixed end cover is provided with an oil seal assembling slot corresponding to the position of the outlet, wherein the single-lip oil seal is assembled in the oil seal assembling slot in a sealing way through a sealing ring, and the surface of the oil seal assembling slot is covered with a sealing cover.

6. The waterproof dustproof electric push rod of claim 5, characterized in that: the sliding teeth of the outer pipe body are tightly attached to the outer rings of the first anti-swing ring, the piston oil seal and the second anti-swing ring.

7. The waterproof dustproof electric putter of claim 4, characterized in that: the sliding connection assembly comprises a sliding block and a threaded sleeve, the sliding block and the sliding sleeve are both annular, the internal thread is arranged on the inner wall of the threaded sleeve, the sliding block is sleeved outside the threaded sleeve, the sliding block and the threaded sleeve are positioned through two positioning screws, the two positioning screws are axially arranged between the sliding block and the threaded sleeve, one part of the same positioning screw is positioned on an inner wall groove of the sliding block, the other part of the positioning screw is positioned on an outer wall groove of the threaded sleeve 3, and the two positioning screws are positioned on the end faces of the sliding block and the threaded sleeve and are oppositely arranged.

8. The waterproof dustproof electric putter of claim 7, characterized in that: the external screw thread is located the outer wall of slider, is equipped with a plurality of side channels, many rings of recesses and an annular spacing platform on the slider keeps away from its external screw thread's one end outer wall, and a plurality of side channels set up along the axial of slider, and many rings of recesses set up along the radial of slider, and a plurality of side channels and many rings of recess are alternately communicate, and spacing platform is located between many rings of recesses and the external screw thread.

9. The waterproof dustproof electric push rod of claim 7, characterized in that: the inner wall of sliding sleeve and the outer wall of slider rotate spacing cooperation, and the outer wall of sliding sleeve outwards extends has a spacing portion, is equipped with a plurality of material holes of drawing on the terminal surface of sliding sleeve, and when the sliding sleeve cover was located on the slider, external screw thread and spacing platform on the slider were located outside the sliding sleeve.

10. The waterproof dustproof electric putter of claim 7, characterized in that: still be equipped with two on the inner wall of outer tube body and hang groove and a location portion, a plurality of smooth tooth, two hang the axial setting of groove and location portion all along the outer tube body, it has a mount to hang along its axial on the inner wall of outer tube body, the both ends of mount are equipped with the platform of hanging of rectangular shape respectively, two platforms of hanging cooperate with two of outer tube body's two string groove one-to-one respectively, the one end that the outer tube body was kept away from to the mount is equipped with a constant head tank, this constant head tank cooperates with the location portion of outer tube body, the both ends of mount are fixed with micro-gap switch respectively, the sliding sleeve is located between two micro-gap switch, sliding sleeve 1's spacing portion 1 is located the side of mount.